1. Field of the Invention
This invention relates to the field of marine cables, and particularly to methods for making such cables resistant to fouling and stiction.
2. Description of the Related Art
There are numerous situations in which surfaces immersed in bodies of water such as the ocean become fouled by marine life. One such situation involves the use of ‘marine streamers’—i.e., long cables that are deployed in the ocean and used for seismic exploration. Typically, streamers (which can be 75 meters long or more) are spooled for transportation to ships, and are unspooled when ready to be used. A typical example of a spooled steamer cable 10 is shown in FIG. 1.
However, once unspooled into the ocean, streamer cables are susceptible to fouling, especially from barnacles 12; this is seen in FIG. 2. One way to combat this is to apply a toxic coating on the streamer. However, such coatings may be subject to complex regulations.
Another approach is to use a sticky, soft—but non-toxic—coating on the streamer. An example would be the silicone-based coatings current gaining market acceptance as non-toxic ship hull coatings. However, such coatings can lead to a ‘self stiction’ problem in which sections of the streamer stick to each other when the streamer is spooled, thereby damaging the coating.
Barnacle fouling of streamer cables is a serious problem in high fouling waters. There is a need for a non-toxic coating which resists fouling, without adversely affecting spooling.